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New 2-methyl-3-nitrobenzoic acid preparation method

A technology of nitrobenzoic acid and nitro-o-xylene, which is applied in the new field of preparation of 2-methyl-3-nitrobenzoic acid, can solve the problems of high risk, pollution, waste water pollution, etc., and achieve dangerous The effect of small size, little pollution and low cost of raw materials

Active Publication Date: 2015-12-09
黄石市利福达医药化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The existing 2-methyl-3-nitrobenzoic acid product is oxidized by 3-nitro-o-xylene through dilute nitric acid, and an autoclave is used for high-pressure reaction, which is dangerous, explosive, and polluted by nitric acid-containing wastewater Larger, the by-products 2-methyl-6-nitrobenzoic acid and 3-nitrophthalic acid are more, and the yield can only be 27%. Because this method is dangerous and polluting, it causes enterprises to Unable to produce normally

Method used

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  • New 2-methyl-3-nitrobenzoic acid preparation method

Examples

Experimental program
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Effect test

example 1

[0017] Example 1: Put 200g of 3-nitro-o-xylene, 700g of o-dichlorobenzene, 200g of n-hexanoic acid, 12g of cobalt acetate, 12g of manganese acetate, and 6g of tetrabromoethane into a 1000ml four-necked flask with a reflux condenser and a water separator. , feed oxygen to maintain 1.2L / min, raise the temperature to 90°C, keep the temperature at 90-100°C for 18 hours, and separate out about 23g of water, and control 3-nitro-o-xylene ≤ 1% in the sampling, which is the end point of the reaction, if the raw material More, continue to pass through the oxygen reaction until the end of the reaction; cool and filter to get 235g of crude product (containing solvent); the mother liquor is used as the next batch of solvent and then add a certain amount of catalyst, and add 5% of the original amount of catalyst, throw 3-Nitrate The base o-xylene reacts with oxygen again, and the result is the same as the original batch.

[0018] Put 235g of crude product, 1400ml of water, and 45g of causti...

example 2

[0019] Example 2: Put 200g of 3-nitro-o-xylene, 700g of o-dichlorobenzene, 300g of n-hexanoic acid, 4g of cobalt acetate, 2g of manganese acetate, and 4g of tetrabromoethane into a 1000ml four-necked flask with reflux condenser and water separator , keep the air at 3.5L / min, raise the temperature to 90°C, and keep the reaction at 90-100°C for 18 hours, and about 23g of water will be separated out. The control of 3-nitro-o-xylene in the sampling is ≤1%, which is the end point of the reaction. If the raw material More, continue to react with oxygen until the reaction reaches the end; cool and filter to obtain 240g of crude product (containing solvent).

[0020] Put 240g crude product into 2000ml four-necked bottle, 1400ml water, 29g purity is 99% caustic soda, heat up to 50-60 ℃, react for 30 minutes, place separatory funnel, separate oil 35g (use as next batch of reaction solvent) , return the water to the 2000ml four-neck bottle, add 6g of activated carbon, stir and decolorize...

example 3

[0021] Example 3: Put 200g 3-nitro-o-xylene, 200g o-dichlorobenzene, 200g n-hexanoic acid, 10g cobalt acetate, 14g manganese acetate, 16g tetrabromoethane into a 1000ml four-necked bottle with reflux condenser and water separator , feed oxygen to maintain 1.0L / min, raise the temperature to 90°C, keep the temperature at 90-100°C for 18 hours, and separate out about 23g of water, and control 3-nitro-o-xylene ≤ 1% in sampling, which is the end point of the reaction, if the raw material More, continue to feed oxygen reaction, until the reaction reaches the end; cooling and filtering to get crude product 230g (containing solvent);

[0022] Drop into 230g crude product in the 2000ml four-necked bottle, 1400ml water, 73.7g purity is 99% caustic soda, is warming up to 50-60 ℃, reacts 30 minutes, is placed in separating funnel, separates oil 25g (uses as next batch reaction solvent) ), return the water to the 2000ml four-neck bottle, add 6g of activated carbon, stir and decolorize at 5...

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Abstract

The present invention relates to a new 2-methyl-3-nitrobenzoic acid preparation method, which is characterized by comprising: adding 3-nitro-o-xylene, an organic solvent and a catalyst to a reactor, and introducing oxygen gas to carry out oxidation, wherein the oxidation temperature is 90-100 DEG C, and the reaction ending point is achieved when the mass concentration of the 3-nitro-o-xylene in the reactor is less than 1%; carrying out cooling filtration to obtain a crude product, wherein the mother liquor is recovered and recycled; and sequentially performing conventional alkalization method, active carbon decoloration and acidification to obtain the 2-methyl-3-nitrobenzoic acid finished product. According to the present invention, the oxygen in the air is used to replace nitric acid to oxidize the 3-nitro-o-xylene into the 2-methyl-3-nitrobenzoic acid, the oxygen is used to oxidize the 3-nitro-o-xylene, the reaction is the normal pressure reaction, the mother liquor is applied, the yield is up to 80%, and the method is the clean production method with characteristics of low risk, low pollution and low raw material cost.

Description

technical field [0001] The invention relates to a new preparation method of 2-methyl-3-nitrobenzoic acid. Background technique [0002] The 2-methyl-3-nitrobenzoic acid product is made into 2-methyl-3-methoxybenzoic acid through reduction reaction, diazotization reaction and methoxylation reaction, while 2-methyl-3-methoxybenzoic acid Oxybenzoic acid is an important intermediate for the preparation of the new high-efficiency and low-toxicity dihydrazide insecticide methoxyfenozide, which is currently in short supply in the market. [0003] The existing 2-methyl-3-nitrobenzoic acid product is oxidized by 3-nitro-o-xylene through dilute nitric acid, and an autoclave is used for high-pressure reaction, which is dangerous, explosive, and polluted by nitric acid-containing wastewater Larger, the by-products 2-methyl-6-nitrobenzoic acid and 3-nitrophthalic acid are more, and the yield can only be 27%. Because this method is dangerous and polluting, it causes enterprises to Unabl...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C205/57C07C201/12
Inventor 包泉兴成家钢方日青
Owner 黄石市利福达医药化工有限公司
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